Spotify Ltd, which promises a whole new way to listen to music via its Spotify online service, has announced it’s launching in the US. Although still in beta, Spotify is available now to all US residents, either by getting in line and signing up for a free Open account invite, or by purchasing a subscription to its Unlimited ($4.99 a month) or Premium ($9.99 a month) services.

Spotify, which was previously restricted to European citizens, allows users to stream their choice of music from over 15 million available tracks to their computer via the free Spotify application or – with a Premium account – mobile device, including iPhone, iPad and Android.

Spotify will offer the same three levels of subscription to US users as currently enjoyed by European users of the service. The free account – Spotify Open – contains a number of restrictions to its service. First, the service is ad-supported to provide funding for artists in return for their songs being listened to. Second, the service cannot be accessed offline. Third, restrictions to the number of hours per month (10) and number of plays per track (five) are introduced after six months.

Spotify Unlimited ($4.99 a month) removes the ads and all limitations on streaming, while Spotify Premium ($9.99 a month) offers an offline mode, access through supported wireless media streaming systems as well as mobile devices, and improved sound quality.

Spotify also makes it possible to purchase individual tracks and albums, which can then be played offline and without any of the restrictions associated with either Open or Unlimited accounts.

The Spotify client is available now as a free download for computer (Windows and Mac), iPhone, iPad and Android. Although the mobile apps are free, you will need a Spotify Premium account to use them.